Process of annealing metals



(No Model.) A

A. TATRO. -PROCESS 0F ANNEALING METALS.

No. 353,094. Patented Nov. 23, 1886.

I JVVEJVTOR' J.'% 1/4 W WITNESSES WWW rrno STATES JosEPH A. TATRO, or BEAVER FALLS, PENNSYLVANIA.

l PROCESS OF ANNEALING METALS SPECIFICATION forming part of Letters Patent No. 353,094, dated November 23, 1886.

' Application filed January 90, 1888. Serial No. 189,126. (No specimens.) i

To all whom it may c0nccrn.-.

Be it known that I, JOSEPH A. TIiTRo, a citizen of the United States, residing at Beaver Falls, in the'count-y ofBeaver and State ofPennsylvania, have invented certain new and useful Improvements in Annealing Metals, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to certain improve ments. in the process of annealing articles of iron and steel-such as file-blanks and the like; and it'has for its objects to provide a new method of annealing the articles, whereby they are heated and cooled in an air-tight vessel in the absence of "oxygen or oxidizing agents, as-

more fully hereinafter specified, These ob jects I accomp ish by the method hereinafter describedand tltc apparatus illustrated in the accompanying drawing, in which latter is represented a vertical sectional view of an air-' tight flask or retort in which the annealing is effected. r

My invention consists in subjecting the articles to heat when embedded in charcoal or other pure carbon, in the absence of atmospheric air or oxidizing gases, as more fully hereinafter specified, and cooling the articles under the same conditions as more fully hereinafter set forth.

In the drawing, the letter A'indicates a retort, constructed of cast metal or other suitable material, of any convenient form, in the present instance being represented in the shape of a cylinder in cross-section. The'n'pper edge of the vessel or flask, around its mouth, is pro vidcd with a beveled flange, B, forming shoulders under which the inwardly-bent ends of Y the yoke C are adapted to fit and engage.

D indicates a concavo-convox cover, which is providedwith a downwardly-extended flange beveled inwardly to fit over the outer surface of the beveled flange B. The'yokeO,

about midway between its ends, is provided with a'screw-threaded aperture, through which passes a binding-screw, E, the inner end of which bears against the centerof the cover, so as to bind it to its seat and form a gas-tight joint around its edges between its inwardlybeveled flange and the outwardly-beveled flange of the flask.

The letter F indicates a petcock or vent cook, which extends upwardly fromthetop of cles, which may be file-blanks or other similar articles of unannealed iron or steel, are placed in the flask and surrounded by charcoal or other form of solid carbon, as indicated in the drawing. The cover being then properly se- 6 cured, the pctcock or vent-valve being open, the flask is placed in a regenerative or other heating-furnace and heated to the usual temperature. After such temperature has been reached and the contents have been thoroughly heated the petcock is closed, so that no influx of air may take place'in cooling. The whole is then removed from the furnace and slowly cooled.

By this method it will be seen thatthe articles are both heated and cooled in an atmos phere entirely free from free oxygen, and without the use of gases generated in extraneous apparatus, as heretofore practiced, thus preventing the oxidation of the articles and the consequent injury to the same, as upon first applying the heat to the flask or vessel the air contained therein is expelled to a certain extent, and the remaining air as the heat is increased is decomposethits oxyggn combiningwith the incandescent oarbon,"'producing carbonaceous gases having a trace of nitrogen, but consisting principally of carbonic oxide, which is a deoxidizinggas, and prevents any possible oxidation'of the articles. In fact, should the articles be oxidized to any extent when placed in the flask, the developed car bonic oxide at the final heating would dooxidize the same.

In this process the charcoal or carbon is not consumed, as is the case where air or oxygen is admitted to the flask; but the carbon is preserved intact, and can be used over and over again.

I am aware that articles have been embedded and heated in charcoal in vessels or flasks whichoare c0vered,'but not air-tight; but in snchcases the air necessarily enters to a allowed to pass during the initial heating, and

greater or-less extent, which oxidizesthe arsubsequently cooling the articles in the same ticles and injures the'same. -vesse1, n'fter closing thepetcoek to prevent Having thus described my invention, what the admission of air, substantially as specified. z 5

- 5 I claim, and desire to secure by Letters Pat- In testimony whereofl afiix my signature in en't, is v v presence of two witnesses. y y

The method herein described-of annealing e metals, the same consisting in heating the ar- JOSEPH TATRO' ticles packed in charcoal or other puz e carj-Witnesses: 10 hon in an air-tight vessel providedwith a, DAVID Iii/WILKINSON,

petcock, through which the contained air is H H. BENFORD. 

